Tumbler or locking disks for cylinder locks and a lock provided with such disks



April 11, 1967 G. A. GAHMBERG 3,313,134

TUMBLER OR LOCKING DISK-S FOR CYLINDER LOCKS AND A LOCK PROVIDED WITHSUCH DISKS Filed Jan. 22, 1965 FIG. 7

FIG. 4

IN VEN TOR.

United States Patent 4 Claims. 01. 70--376) This invention relates totumbler disks or so called locking disks in cylinder locks of the typeprovided with disks for locking function of the cylinder as shown in theFinnish Patent 7,203. In this type of locks a number 'of disks of theshape as shown in FIG. 1 and FIG. 4 are used instead of pins or plungersas for example in Yale or similar locks. The cylinder contains a numberof such disks separated from each other by flat and thin disksprings andheld within the cylinder by a spring exerting a predetermined pressureranging from 1 kgr. to 4 kgr. The disks can be rotated in the cylinder acertain angle by the use of the key. The cylinder is open at one end andthe cylinder wall has two longitudinal slits reaching from the open endto the bottom. The lug on the periphery of the disk enters into one ofthe mentioned slits and limits the movements of the disk. In the otherslit a so called flocking bar or pin is placed. The locking pin has alength corresponding to the length of the batch of the locking disks. Inthe wall of cylinder housing is longitudinal groove with a depth ofabout half of the locking pin, so that when the locking pin rides uponthe circumferences of the locking disks half of the body of the pinrests in said groove and the other half remains in the cylinder wallslit, locking the cylinder to its housing.

Each locking disk is provided with a notch in its periphery, differentlyspaced in each disk of the batch and arranged so that, when the disksare rotated by the action of the key, they can be lined up forming acontinuous groove. When this groove, turning the key, comes opposite theslit in the cylinder wall, in which slit the locking pin rests, the pinwill be forced out of the cylinder housing groove and into the lined upgrooves of the disk batch. The depth of the groove formed by the linedup notches in the locking disks, is about half of the locking pindiameter, thus the disk batch and the cylinder are locked to each otherand by further turning of the key the cylinder takes part in the turningmovement, which in known way is transmitted to the latch bolt.

This simple design of the locking disks has, however, the disadvantagethat it has shown to be possible by introducing through the keyhole inbetween a disk and the adjacent diskspring a suitably bent thin burglarstool ending with a small hook to feel how the said peripheral notchesare located and line them up or choose a suitable skeleton key.

In order to make the locating of the peripheral operative notches on thelocking disks more diflicult, the disks were later provided with one ormore indentations on one or both sides as disclosed in the FinnishPatent 25,707.

It has been proved that even these notches intended as misguidingindentations in the sides of the locking disks have not been effectiveenough to prevent the picking of the lock.

In order to obviate this disadvantage, the locking disks according tothe present invention have been provided with one or more additionalnotches arbitrarily spaced along their periphery, these additionalnotches preferably having the same spacing as the previously mentionedindentations in the sides of the disks. Also, the additional notches maybe combined with the indentations, and may have the same peripherallength as the indentations.

One or several or even all of the locking disks in a cylinder may beprovided with such indentations and ad ditional notches making thepicking of the lock practically impossible or at least extremelydifiicult.

The invention will further be described by way of example with referenceto the accompanying drawing showing two embodiments of the invention.

FIG. 1 shows a side view of a locking disk with the indentations only onone side,

FIG. 2 shows a part of the circumference of the disk in FIG. 1 as seenin the direction of the arrows I- I,

FIG. 3 shows a part of the circumference of the disk in FIG. 1 as seenin the direction of the arrows II-II,

FIG. 4 shows a side view of a locking disk with the indentations on bothsides,

FIG. 5 shows a part of the circumference of the disk in FIG. 4 as seenin the direction of the arrows II I--III,

FIG. 6 shows a part of the circumference of the disk in FIG. 4 as seenin the direction of the arrows IV-IV.

In FIG. 1 each locking disk 1 is provided with an operative notch 2 inits circumference for the locking pin (not shown), an additional foolingnotch 3, and, further, with two indentations 4 on the same side of thedisk. The spacing of the indentations 4 is arbitrary. As shown in FIG. 1and FIG. 3, the additional fooling notch 3 may be combined with one ofthe indentations 4.

FIG. 3 shows a locking disk 1 with the indentations 4 made on bothsides. The spacing of these on each side is arbitrary and theindentation 4 can also be combined with the circumferential foolingnotches 3 as shown in FIG. 6. The spacing of the indentations 4 can beequal on both sides of the disk and they can thus also be locatedopposite each other as shown in FIG. 5 and FIG. 6.

The number of circumferential fooling notches 3 as well as the number ofthe indentations 4 in the side surfaces of the disks is arbitrary aswell as their spacing. This makes it exceedingly difficult and tediousor almost imposible for a lock-picker to locate the operative lockingpin notches 2 in all the disks in a lock cylinder and bring all thenotches 2 in line allowing the locking pin to fall into the grooveformed by the lined-up notches 2;; thus allowing the cylinder to beturned in its housing and the latch bolt to be withdrawn and the dooropened.

What I claim is:

1. A locking disc for cylinder locks, said disk being provided with anoperative notch cut in the circumference thereof and adapted to seat alocking bar; at least one indentation formed in at least one side of thedisk in order to make locating of said operative notch difiicult for alock-picker, said indentation having the same outline as said operativenotch and being located similarly, separately, and with an arbitraryspacing along said disk; and means for misleading the lock picker whichdo not detrimentally interfere with the movement of said locking baralong the circumference of said disk, said means comprising at least oneadditional notch formed in the circumference of the disk, saidadditional notch having the same circumferential length as saidoperative notch and a smaller depth than said operative notch.

2. The locking disk of claim 1, wherein the location of said additionalnotch wit-h respect to said disk coincides with that of saidindentation.

3. A cylinder lock comprising a plurality of coaxial spring loaded disksin juxtaposition, each of said disks being provided with an operativenotch cut in the circumference thereof, said operative notches togetherbeing adapted to seat a locking bar when aligned; at least oneindentation formed in at least one side of each disk in order to makelocating of said operative notch diflicult for a lock-picker, saidindentation having the same outline as said operative notch and beinglocated similarly, separately, and With an arbitrary spacing along saiddisk; and means for misleading the lock-picker Which do notdetrimentally interfere With the movement of said locking bar along thecircumference of said disk, said means comprising at least oneadditional notch formed in the circumference of each disc, saidadditional notch having the same circumferential length as saidoperative notch and a smaller depth than said operative notch.

4. The lock of claim 3, wherein the location of said additional notchwith respect to said disk coincides with that of said indentation.

2,301,755 11/1942 Seiffert i 70-376 X 5 2,613,528 10/1952 Salmivuori70-366 FOREIGN PATENTS 25,707 4/ 1952 Finland.

10 EDWARD c. ALLEN, Primary Examiner.

P. TEITELBAUM, Assistant Examiner.

1. A LOCKING DISC FOR CYLINDER LOCKS, SAID DISK BEING PROVIDED WITH ANOPERATIVE NOTCH CUT IN THE CIRCUMFERENCE THEREOF AND ADAPTED TO SEAT ALOCKING BAR; AT LEAST ONE INDENTATION FORMED IN AT LEAST ONE SIDE OF THEDISK IN ORDER TO MAKE LOCATING OF SAID OPERATIVE NOTCH DIFFICULT FOR ALOCK-PICKER, SAID INDENTATIONHAVING THE SAME OUTLINE AS SAID OPERATIVENOTCH AND BEING LOCATED SIMILARLY, SEPARATELY, AND WITH AN ARBITRARYSPACING ALONG SAID DISK; AND MEANS FOR MISLEADING THE LOCK-PICKER WHICHDO NOT DETRIMENTALLY INTERFERE WITH THE MOVEMENT OF SAID LOCKING BARALONG THE CIRCUMFERENCE OF SAID DISK, SAID MEANS COMPRISING AT LEAST ONEADDITIONAL NOTCH FORMED IN THE CIRCUMFERENCE OF THE DISK, SAIDADDITIONAL NOTCH HAVING THE SAME CIRCUMFERENTIAL LENGTH AS SAIDOPERATIVE NOTCH AND A SMALLER DEPTH THAN SAID OPERATIVE NOTCH.